Resistance or fuse wire



Patented 1942 I UNITEDSTATES PATENT OFFICE RESISTANCE R FUSE WIRE Cecil Spencer Sivll, Roselle, N. a, assignor to Baker & Company, Inc., Newark, N. 1., a corporation of New Jersey No Drawing. Application December 20, 1941, 1 Serial No. 423,782

6 Claims. (Cl. 201-76) This invention relates to wires suitable as elecruthenium, with a corresponding maximum trical resistances particularly in the ignition of amount of 17.5% for each of the rhodium and explosives, such as resistance wires or bridge ruthenium constituents. .Such alloys have exwires in blasting caps, detonators and the like. cellent corrosion resistance and their 'melting Heretofore such resistance wires for igniting points are in excess of the ignition point of deor setting ofl explosives usually consisted of an tonating charges. As such alloys have, further,

alloy of platinum-iridium containing from 10% highelectrical resistance and great strength they to'20% iridium, the alloy of 80% platinum and are admirably suited for such purposes as re- 20% iridium generally being preferred. Such sistance wires or bridge wires in blasting caps,

alloys of platinum-iridium are, however, very 10 detonators and the like. expensive. In a co-pending application Serial 1 have found particularly satisfactory elec- No. 288,572, filed August 5, 1939, I have described trical resistance wires of such specific alloys as electrical resistance wires of alloys of platinum palladium-5% ruthenium, 90%P 1 with palladium and ruthenium containing from 5% ruthenium-5% rhodium, and 95% palladium- 10% to 80% platinum, from 12% to 90% pal- 15 5% rhodium, i. e.' alloys of 90% to 95% palladium ladium, and from 1% to 15% ruthenium, which and 5% to 10% of metal taken from the group alloys have been found to be highly satisfactory. rhodium and ruthenium. The alloys have a h h It is one object of my invention to produce an melting p int nd l w Specific y- I m y electrical resistance wire which shall consist provide, for instance, 7 00 feet of 0.0015" elecsubstantially of precious metals only and shall trlcal resistan e Wire fr m 1 Ounce f l y o have low specific gravity, high electrical resistp lladi mh m. n lloy wh h ance and satisfactory breaking loads or tensile has aspeciflc vi y o n a melting point strength to take the place oi. fuse wire of platiof 1600 C. The particular'feature of the elecnum-iridium alloys heretofore in general use in trical resistance wire according to the present insetting of! explosives, and which while having vention is that it is comp ely Sa is y withcharacteristics similar to those of such platinumut the p esence o an p at u w e e y t is iridium wires shall be of considerably lower 'cost. P l o t f l a v n ge f the extremel It is another object of my invention to prolow price nd l w p fi v y of p i m. duce such wires for such purposes as resistances although of course the alloys m y contain some in Wheatstone bridges, resistance coils and re- 30 p t l ise. the spec fic ty of osistance wires for use in igniting explosives, as dium as well as ruthenium is extremely low. in blasting caps,,detonators or the like. A still 1 What I-claiin is: further object of my present inv nti i t 1. An electrical resistance wire consisting of vide such resistance wires which shall be cheaper the alloy Of to 95% palladium and 5% to than the resistance wires described-in my 00- 5 20% of metal taken from the group consi pending application above referred to and yet of of ruthenium and rhodium. e al quality or'even superior quality. 2- An electrical resistance wire consisting of This application is a continuation in part of an al y f to 95% palladium, to my application No. 378,376, filed February 11, ruthenium, and 2.5% to 17.5% rhodium, wherein 1941. l 40 the combined content of ruthenium and rhodium The electrical resistance wire of my present indoes not exceed 20%. vention consists of an alloy of palladium with at i 3. An electrical resistance wire consisting of least one metal taken from the group consisting an alloy of 90% to 95% palladium, and 5% to of rhodium and ruthenium in the proportion of 10% of metal taken from the group consisting of not less than about 80% palladium and not more ruthenium and rhodiumr than about 95% palladium alloyed with 5% to 4. An electrical resistance wire consisting of 20% of such metal of the group rhodium and a-n'alloy of 90% to 95% palladium, 2.5% to 7.5% ruthenium. In no case should the alloy contain ruthenium, 2.5% to 7.5% rhodium, wherein the less than 5% of rhodium or ruthenium or of combined content of ruthenium and rhodium rhodium and ruthenium. If the electrical resistdoes not exceed 10%. V

ance wire is construct d of a substantially binary 5. An electrical resistance wire consisting of alloy, the alloy should contain, therefore, at least an alloy of about 9 palladium and about 5% 5% rhodiumor 5% ruthenium; if the electrical ruthenium.

r sist n ir i h tru t d 1' a ub- 6. An electrical resistance wire consisting of stantially ternary alloy, the alloy should, therean alloy of about palladium, about 5% fore, contain at least 5% rhodium and ruthenium ruthenium, and about 5% rhodium.

such, for instance, as 2.5% rhodium and 2. CECIL-S. SIVIL. 

